Airplane



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I T. P! LE MANQ AIB PtANE. APPLICATION FILED IULY I. 1918.

1,304,525. Patented May 20, 1919.

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T. P. LEAMAN.

AIRPLANE. APPLICATION FILED my I. ma.

1,304,525. Patented May 20, 1919.

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THOMAS P. LEAMAN, 0F ITHAGA, NEW YORK.

AIRPLANE.

Specification of Letters Patent.

Patented May 20, 1919.

Appfieation filed July 1, 1918. Serial No. 242,725.

To all whom it may concern:

Be it known that I, THOMAS P. LEAMAN, a citizen of the United States,and resident of Ithaca, in the county of Tompkins and State of New York,have invented certain new and useful Improvements in Airplanes, of whichthe following is a specification.

This invention relates to airplanes, and my improvements are directed toa novel means of mounting the main supporting wings or aerofoils so thatthey may be controlled to vary their angle of incidence, whereby inhorizontal flight, a, flatter angle may be provided for high speeds;while for making landings, and for rising, as also for lateral controlthe wings may be given varying positive and negative angles.

Different methods have been tried where.- by the main supporting wingsof airplanes are mounted for movement to variable degrees of angularity,but the object sought in my present invention is that of providing ajoint whose engagement extends over a substantial extent of the wingchord, in the interest of strength and rigidity, and in imparting tosaid joint a compound flexure; in order that, when the wings are movedupon their hinges, to vary their angle of incidence, they will notnecessarily shift out of the horizontal plane normally occupied by theirspan or spread. In other words, if the normal span of the wings be fiat,or with a given dihedral, the same may be undis turbed through themovements of said wings about their joint.

In brief, the compound wing joint'I have devised consists of a central,longitudinally disposed hinge and a pair of angularly disposed hingesengaging the butt ends of a pair of wings, which converge at one end ofsaid central hinge, and together inclose a triangle which is bi-sectedby said central hinge. By means of this compound joint, the wings, inflexing, may turn upwardly or downwardly around the central hinge, atthe same time turning equally in the opposite direction upon the outer,inclined hinges, to remain, with the new angle of incldenoe, insubstantially the normal plane of their span.

Suitable control means are provided whereby the right and left wings aremoved in synchronism.

Variation of speed.

It will be evident from the foregoing that if the opposite surfaces aresimultaneously raised or lowered, through the medium of the compoundjoint, their respective angles of incidence are decreased or increased,thus providing a means for varying, during flight, the horizontal speedof the machine.

Lateral control.

It is also evident, that if one wing be raised while the opposite islowered (by means of the compound joint) the angle of incidence of onewing will be increased while that of the opposite wing decreases orbecomes negative. This provides a simple and very powerful means forlateral control.

Longitudinal control.

Longitudinal control may be performed through the tail elevators, bymeans of cables leading to a universally mounted joy stick.

Directional control.

Directional control may be through the conventional foot bar connectedby cables to a vertical rudder.

Other features and advantages of my said invention will hereinafterappear.

Figure 1 is a rear elevation of a bi-plane embodying my improved jointedwings.

Fig. 2 is a top plan view thereof.

Fig. 3 is a detail of control mechanism for the jointed wings and thetail wings.

Fig. 4: is an enlarged section through the line H of Fig. 2, and

Fig. 5 is a rear edge view of the wings (when the angular hingesconverge forwardly) showing in full lines the normal position thereof,and showing the joints flexed (in dotted lines) for an increased angleof attack.

My improvement is here shown as applied to a bi-plane, but it is equallyapplicableto monoplanes or multiplanes.

The bi-plane illustrated has the upper wings 1, 2; lower wings 3, 4:,and connecting struts 5, 5 which latter have pivotal engagement with thewings, as by ball and socket joints.

The central portion of the supporting surface of both upper and lowerwing spreads is in the form of a plane triangle whose base is includedin the rear edge of said surface, and its vertex in the leading edge;and said central portion is divided centrally, by a longitudinallyextending hinge 6, into the triangles 7, 8, whose outer edgesrespectively, oppose, and engage by hinged connections the butt ends ofthe wings.

For convenience, in the following description, the wings 1 and 3 may bereferred to as the left wings, and the wings 2 and l as the right wings.

An example of means for effecting the hinge connection is shown in theenlarged, sectional view of Fig. 4, indicating the central hinge 6, andthe forwardly converging hinges 9 and 10, at opposite sides thereof. Thehinge 6 is formed about a rigidly mounted shaft 11, upon which theportions 7, 8, may turn; while, the left and right wings may,respectively, turn about the hinges 9 and 10.

Since it is my purpose, in providing the compound joint aforesaid, toeffect changes of incidence angularity through chord-wise fieXure, Icause the portions 7, 8, to be turned upon hinge 6 oppositely to theturning movement of the left and right wings, whereby the desired resultis achieved.

Therefore, rear struts 5 are engaged with the hinges 9, 10, near therear ends of the latter, and the fiexure of the compound joint isaccomplished by moving said struts up or down.

Should the portions 7, 8, be thus turned downwardly, then, bearing inmind that the upper and lower wings are trussed together, and eachprovided with corresponding joints, it will be apparent that while therearward edge of the wings will be depressed, the leading edge willremain stationary, or, according to the degree of motion imparted, willtend to slightly increase in dihedral. If, on the other hand, theportions 7, 8, are turned upwardly, then the opposite effect willresult; the rear edge rising, and the leading edge remaining stationary,or with a tendency toward a cathedral angle. The movements aforesaid areof course rendered possible by reason of the jointed connections betweenthe struts and wings. By these movements the wings have imparted to themthe desired changes in incidence angularity, as for lateral control andfor varying the speed of flight.

The control means illustrated herein,

whereby the wings are moved, consist of bell-cranks 12, 13, ournaled onfixed pivots 14:, and having pivotal connection with the struts 5. Saidbell-cranks engage, respectively, with left and right threaded rods l5,16, that enter oppositely threaded ends of a tube 17, which is providedwith a handwheel 18, for rotation.

Upon turning the hand-wheel in one direction the rods 15, 16, will bedrawn inwardly, thereby causing the struts 5 to be lowered. This actionwill depress the rear edges of the wings, as shown in dotted lines,Figs. 1 and 5, and thereby increase the attacking angle. Whereas if thehand-wheel be turned in the opposite direction the rear edges of thewings will be raised and correspondingly decrease the attacking angle orrender it neutral or negative, according to the degree of movementemployed.

The above operation is utilized for changing the angle of incidence inflight, and consequently varying the speed and climb of the machine.

For lateral control the joy stick 21 is connected throughuniversal'joints 23, and link 2a, to a collar 25, said collar beingcapable of revolving about tube 17 but incapable of sliding thereon.Lateral motion of the joy stick 21 will therefore cause tube 17 to bedisplaced laterally, which action, through the bell cranks 14, willcause one strut 5 to move downwardly, while the opposite strut 5 movesin an upward direction, thus increasing the angle of incidence of thewings on one side of the machine, while the angle of the wings on theopposite side is reduced a like amount. This action produces a strongrighting moment for lateral control.

For longitudinal control the joy stick 21 is connected to tail elevators19 by cables 20 in the conventional manner.

Directional control is imparted by a vertical rudder 26, which isoperated by cables 27, leading to a foot bar 28, as in current practice.

Variations may be resorted to within the spirit and scope of my saidinvention and parts thereof used without others.

I claim 1. An airplane having supporting wings engaged by co-actinglongitudinal and angular chordwise hinges, whereby said wings aremovable to variable angles of incidence substantially without change inlateral angularity.

2. An airplane having supporting wings engaged floy co-actinglongitudinal and angular chordwise hinges, whereby said wings aremovable to variable angles of incidence substantially without change inlateral angularity, and control means for said wings.

3. The combination, in an airplane, of

right and left supporting wings therefor,

244. AERONAUTlCS movable to variable angles of incidence, a larity atthe respective sides of said central central chordwise connecting hingefor said hinge, and control means for said Wings. Wings, and chordwisehinges of opposite Signed at Ithaca in the county of Ithaca angularityat the respective sides of said and State of New York this 10th day of 5centr ailhhinge. b 1 f June A. D. 1918.

4. e com ination, in an airp ane, 0 right and left supporting Wingstherefor, THOMAS LEAMAN' movable to variable angles of incidence, aWitnesses: central chordwise connecting hinge for said F. W. BARKER, 10Wings, chordwise hinges of opposite angu- A. B. BARKER.

copies of this patent may be obtained for five cents each, by addressingthe commissioner of Patents, Washington, D. G.

